The present invention relates to an electrical contact which is used to prevent microrubbing wear.
Electrical connectors used in automobiles may be subjected to vibration depending on the use of the connector. When such electrical connectors vibrate, microrubbing occurs between the electrical contacts and their respective mating contacts. As a result of this microrubbing, wear occurs between the contacts, causing the electrical resistance at the connection to increase.
For example, a known receptacle terminal 100 is shown in FIG. 5 and disclosed in Japanese Patent Application Kokai No. HEI 7-296886. This receptacle consists of an inner body 110, and an outer body 130. The inner body 110 is equipped with a contact member 111 which has an elastic contact section 112 that contacts the mating contact (not shown in the figures), a wire receiving section 113, and a spring 116 which is formed between the contact member 111 and the wire receiving section 113. The wire receiving section 113 consists of a wire barrel 114 and an insulation barrel 115. A projection 125 is formed so that it protrudes from the bottom wall 117 of the inner body 110 at a point located further toward the wire receiving section 113 than the spring 116. This projection 125 engages with an opening (not shown in the figures) formed in the bottom wall of the outer body 130 to fasten the inner body 110 and outer body 130 together. The spring 116 is constructed from a plurality of elastic girders 123 separated by a plurality of slots 119, 120, 121 and 122 which extend through the bottom wall 117 and side walls 118, so that the spring 116 has elasticity in the axial direction. The respective elastic girders 123 are connected by bridge parts 124 that are deformable in the plane of the side walls 118.
This receptacle terminal 100 is inserted into a connector housing (not shown in the figures), and is anchored to this connector housing by lances 131 formed on the side walls of the outer body 130. In this case, as a result of the presence of the spring 116, the contact member 111 of the inner body 110 can be freely and independently moved in the axial direction. In cases where the connector is subjected to vibration, the outer body 130 and the portion of the inner body 110 that is located further toward the wire receiving section 113 than the spring 116 vibrate. However, since this vibration is absorbed by the spring 116, the contact member 111 does not vibrate, so that microrubbing with the mating contact is prevented.
Another example of a known contact is shown in FIG. 6 and disclosed in Japanese Patent Application Kokai No. HEI 10-189102. This electrical contact 200 consists of a receptacle 210 that accommodates a mating contact (not shown in the figures), and a wire receiving section 220 to which an electrical wire is connected. The receptacle 210 is equipped with a top wall 212 which extends from the upper end of one side wall (not shown in the figures) toward the other side wall 211, a connecting part 213 which extends from this second side wall 211 toward the first side wall, and a contact member 214 which extends from the end of the connecting part 213 and contacts the mating contact. Here, the width of the connecting part 213 is set so that it is considerably narrower than the width of the side wall 211. The connecting part 213 is thus constructed so that it has elasticity in the axial direction.
This electrical contact 200 is inserted into a connector housing (not shown in the figures), and a lance formed on the housing engages with an opening in the bottom wall of the receptacle 210, so that the electrical contact 200 is anchored to the connector housing. As a result of the presence of the connecting part 213 which possesses elasticity, the contact member 214 can move freely and independently in the axial direction inside the receptacle 210. In cases where the connector is subjected to vibration, the outside portion of the receptacle 210 vibrates. However, since this vibration is absorbed by the connecting part 213, the contact member 214 does not vibrate, so that microrubbing wear with the mating contact is prevented.
Yet another known electrical contact is shown in FIG. 7 and disclosed in Japanese Patent Application Kokai No. HEI 10-149855. This electrical contact 300 consists of two bodies, an internal body 310 and an external body 320. The internal body 310 has a contact member 311 that contacts the mating contact (not shown in the figures), and a lead part 312 that extends rearward from the rear end portion of the contact member 311. Furthermore, the external body 320 is equipped with an enveloping body 321 that supports the contact member 311 of the internal body 310 so that play is possible in the axial direction, and a wire receiving section 322 which positions the lead part 312 of the internal body 310 on the inside, and to which an electrical wire (not shown in the figures) is connected.
This electrical contact 300 is inserted into a connector housing (not shown in the figures), and a lance formed on the housing engages with an opening in the bottom wall of the enveloping body 321, so that the electrical contact 300 is anchored to the connector housing. The contact member 311 can move freely and independently in the axial direction inside the enveloping body 321, and the lead part 312 possesses flexibility so that it can flex in the axial direction. In cases where the connector is subjected to vibration, the enveloping body 321 and wire receiving section 322 vibrate. However, the contact member 311 does not vibrate, so that microrubbing wear with the mating contact is prevented.
The following problems have been encountered in these known electrical contacts. In the case of the receptacle terminal 100 shown in FIG. 5, the transmission of vibration to the contact member 111 is reduced as a result of the presence of the spring 116. However, since this terminal consists of two bodies, the outer body 130 and inner body 110, there are difficulties in terms of the ease of assembly and manufacture of the contact. Furthermore, since the spring 116 is constructed from a plurality of slender elastic girders 123, an extremely slender conductive path is formed in the spring 116, so that this structure is unsuitable for the flow of a relatively large current.
In the case of the electrical contact 200 shown in FIG. 6, as in the receptacle terminal 100 shown in FIG. 5, the transmission of vibration to the contact member 214 is reduced as a result of the presence of the connecting part 213 which acts as a spring, but a slender conductive path is formed in the connecting part 213.
Similarly, in the case of the electrical contact 300 shown in FIG. 7, as in the receptacle terminal 100 shown in FIG. 5, a slender conductive path is formed in the lead part 312, and since the contact does not consist of a single part, there are difficulties in terms of the ease of assembly and manufacture of the contact.
The present invention was devised to address these problems. An object of the present invention is to provide an electrical contact which has favorable assembly characteristics and is easily manufacturable, and which can allow the flow of a relatively large current and reduce microrubbing wear without using a spring that reduces the transmission of vibration to the contact member from the outside.
The electrical contact has a contact member that contacts the mating contact. The contact member has a first resilient contact arm which extends rearward from the lower top wall, a connecting section which is bent downward at the rear end of the first resilient contact arm, and a second resilient contact arm which extends forward from the connecting section. In cases where the mating contact tends to be pushed further inward after the insertion of the mating contact has been completed, the area in the vicinity of the rear end of the first resilient contact arm 16a contacts the upper top wall.